The proposed research has two aims: (1) to develop a novel within-subject experimental methodology for analyzing learned behavioral tolerance to drugs, and (2) to apply that methodology to the detection of the ethanol-compensatory "conditioned arousal" responses that are predicted by Siegel's (1979) Pavlovian conditioning theory of drug tolerance. While performing either a motor task or a cognitive task, animal subjects will be given Pavlovian drug-conditioning trials of one cue (CS+) paired with alcohol and another cue (CS-) paired with a placebo. During conditioning, behavioral tolerance will be monitored as gradual decreases in alcohol-induced performance deficits. After conditioning, test trials of CS+ -and-placebo will permit the observation of "conditioned arousal," revealed as above-baseline performance (cf. Lightfoot, 1980) when compared to performance in the preceding CS- baseline session. The "conditioned arousal" effect may also be revealed during the conditioning phase as anticipatory arousal (i.e., enhancement of performance) in the early portion of drug sessions (i.e., between exposure to the CS+ and the onset of the unconditioned ethanol effects). The demonstration of conditioned ethanol-compensatory responses would have important implications for the etiology and treatment of problem drinking. A well-developed, economical animal model of learned tolerance would make possible further studies of the relationship between tolerance and withdrawal, as well as studies of cross-tolerance between drugs that would be dangerous to perform with human subjects.